Can an immune response to certolizumab pegol reduce its effectiveness?

The study looked at the immune response of patients with rheumatoid arthritis to certolizumab pegol (Cimzia) and the effect this has on response to the drug. The authors concluded that patients who develop an immune response to certolizumab pegol have lower levels of the drug in their system after 12 months, and that higher levels led to better RA control.  

In rheumatoid arthritis (RA), the immune system attacks the healthy joints the way it would a virus or bacteria. Certolizumab pegol is a common biological drug used to treat RA. This drug works by blocking the activity of proteins that are known to contribute to the over-activation of the immune system.

One possible consequence of treating RA with a biological drug is that the body can have an immune response against these drugs. Typically, the immune system produces antibodies to clear infections from viruses and bacteria. If a patient with RA is treated with a biological drug, sometimes the immune system responds by producing antibodies that will clear the drug. These are called anti-drug antibodies (ADAbs). If this happens then these patients will have less of the drug in their system and may not respond as well to this type of treatment.

This trial examined whether ADAbs against certolizumab affected disease response to treatment. 112 RA patients receiving treatment with certolizumab were included in this study. Blood samples were taken at 3, 6 and 12 months to measure the levels of ADAbs. Disease activity was also measured at each visit.

By 12 months, 37% of patients produced ADAbs in response to treatment with certolizumab. Patients who produced ADAbs had significantly lower levels of the drug in their system than those who had not. ADAbs were not associated with disease activity. Higer levels of the drug were associated with improved disease activity. 

This study concluded that patients who have an immune response to certolizumab have lower levels of the drug in their system after 12 months. Lower drug levels affected the disease activity in these patients.

This study was carried out on a small number of patients. Some of the patients were also receiving other treatments and this may have interfered with the results.